SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48caa4d0f5c2fe91c8a7ebc2acf6b697c42f061459e12b01ae9daedd2e3391c9' 
  AND token = 'dNDxkqnNWa67gYQJykd9faWrCTUB6FqTG6bfpEsarW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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