SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dadca55dc63fc67c20881d9a6bd8ef08b848200df8121ed6e6148829d9f454da' 
  AND token = 'hMy7Nor+L6bsNlHNSIRANo5vOjtSkL7OodgtzcLJhLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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