SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '59e2a85857c5f776a3741f45bf0d829a1827e31a0692bc639f50ee7ebbb856fe' 
  AND token = 'tZ/DpRx+kE+Yuf0hqhA5Lm1zlh52qZgdTT2xg2fxiv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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