SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2e230206ea8d565f95f29b3db3931163cc7c4fb482b1ab3028fffad06e34641' 
  AND token = 'vSRyg5lSPaKC0sciXxfQj/93596R46fJLaN3kjcBof4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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