SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10840298ed0c40319e86fc269c82e9baeba46124fdfdc59c66d921b126ddd05e' 
  AND token = 'Ii680X3aIEYUJLAUi6VVNYqu+BUcrytx1Rjk5D7nx90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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