SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17b0b71371dade8c7e69af0df835479a1b9ee8ab872106d68cb0cd64b9ab9a89' 
  AND token = 'JC5suRBXa7mGNQhXlGSxpc7hFYsAZ5s1hsX4yui7Nfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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