SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '381774334cf6a364b04359dec78911364209c2de94ce0add316aec0ecea50e21' 
  AND token = 'FqTY1mE3FgL9WoZyYHWXVUdnxRweJReJe9PHyQyOlrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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