SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c2bc46c54a05f4b3a64c7412d20e1347f1e3118e3d0fcfe5ff47a6c5b66fb5d' 
  AND token = 'UX/+vEO9y4K0HcvURkE4P7PQrvP3n5i4CzYg/EzLQGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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