SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a03fecc98c4a52069045080f39450425506f74b3ba199cc4729feb02016716e5' 
  AND token = 'wDDSTT+rNqAxtr/Og7zA3JmfZMNhAKkapcF7W0tBREg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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