SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '20e36203b5730be2aba29d169ef85ebff90cb6d53d7c5db3608e76b2ff9bc5f6' 
  AND token = 'KGUObJa2Rk6iWiPF/Dx2zZAxJ3w+KW1aGc2eg3vfQ+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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