SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e978e81735d55bc39c44fb8bdfacbd8d20e935149beefca2badafabdd457412d' 
  AND token = 'TlDvYEwUn6Vx0iekdsOhg+lbWraI8AaM9hmeM4TYZvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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