SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e843b9d4d93600eec07cbe42ac27fbc0479f900da29de6b572a9f74807d6e353' 
  AND token = 'bs6pez1+rvO5gEk8nSwS3Xjp0qXiSIx9gN4mfStbaZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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