Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4643f26aa62282159e586ac8ddca39b750829d9eab3aa1896a26728022ded980' 
  AND token = '9yWYMYjkEiPZ/pqih8K/BzlyiSjlcvZTy9JoxF33Cy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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