SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce8366cbe5a74a51eabbeb8f50d90e43fc4519864bb0cd0d09bb53d1fb30b98a' 
  AND token = 'kEgtU30C1FScJOcA6Bzr3KylkfxRDkFJUaHCAT/bxaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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