SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bdcd6200532e62ea6e5d641097a3eb48540f3b92f14a35fbb92762a4ed7802c2' 
  AND token = '48Ko6k+JZFvlEk/Ox1h3PYDqhhBA5V3LQ5RM5vqjBYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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