SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d8b82737133c7997facfb7bbac9cf12b7c67d63b544d7452e35432fe2b63aa4' 
  AND token = 'LsN9uxzBhOwDzSjPJJhvIabSdSGDdBykLqRL4Ki2fEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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