SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '851112897910476800503ce96df5859a46cd8870f916bb2e04f0cf073438fe61' 
  AND token = 'rJqdfmbHh/b3rrFICBUv110ozVGjCiX1V4V2knrEA4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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