SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f296664e49e5beec380d270688e901be287a3148136078f2df4dc9ab1d7428b0' 
  AND token = '8YNjZF3ZyGdEoVnbGez2pmxk8VubYdlfWdl5pz7zo+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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