SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42c8145e4411172bc4b8665ba37c311aae52099d05bd70c9aaf56256b3781b35' 
  AND token = 'AoME6UzuPYlnklF6r3c5pzESkONKfh5pbtIyy3xSvUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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