SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36ad697b16db0ceb00fb09ae8308e576a7810bcb114252957f2418df6bdd8220' 
  AND token = 'JWhSIYkqPE/BDX6pl5FV0pK008grNsWr1T2NKyk+r+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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