SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '342dd3d7adcd7b1956c667d0feb2272b9c522ff76fdfc85bdeca198ecd678a78' 
  AND token = 'GxfcqzLgGJrLgBmAo4Y8nqJyFfvUKw4Y0i4fFFqICGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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