SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4823e57a676f9220a9642d862aae763ddd72d718e2dfbebc52d67d9d7cde823a' 
  AND token = 'AMEiXSl2HoZMDPzBdAUjXjW916F59evtvTpyBNKzF04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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