SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e0c46740b17ebe62981b6bfe45ac013109cb256aa29677060b278b051e6a2b8' 
  AND token = 'jPw1pCjo3CopTs6QtUR2UEC8JMQjK1j9puPKpGqEOk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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