SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f45195ee84d83e4d719ad1d836e5039390d3fcf57afcf08a970c4ab64274b248' 
  AND token = 'G8d5rcmhDUfJx0Y8wM6PNHk0V0iTJCO5/i7WJQz58Aw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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