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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b92de9d7afe8e5c896c75b061a7f5c1d29fc5de0de67de5f08ba996ec58d8b2' 
  AND token = 'idFC8aNssEKBkcdpExINknMWCGFffVVI7dbP48k4sJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}