SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1b4bae9c4225b3dcaae0d483ff77ed49e0927009e90b262ab0bd2687ee88a2c1' 
  AND token = 'Lk3EJRt0E1BCWusOB3t9nnOONnFLZGYa5fSO0SM3QGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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