SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa8992108a4e3c72864aa0aecfad99886a2ccf12d36124a9d84880a96cb4bf73' 
  AND token = 'CIJ7LILn2PYPCOre3DuN+hMzMCYCLlfqkjsPBA66Atw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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