SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de9c70724360896c0d967009477b23caa49bf75cdee58c474f66b1849d28e534' 
  AND token = 'beYsn2gfFjQG7Gsm6qpSa0a1qMihUeEsnj9CGDAewBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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