SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b45c4fbea0daa876230c4f2906c6f5028c3d77d901d842034c29a502bd8d610a' 
  AND token = 'RixDbMiJD8Y/tNpgZOHhZM+ZLsEPQ9rVzb4hyVBQJQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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