SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c26878f9416b32f1169aaa5558b033349ff42a27d67a6dee239f4e6673a81b3' 
  AND token = 'qNqOPWNQmrgSOq4JzSiypHC6Kcwfv1BPRGjfR4HtHc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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