SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ff231aff3ba3f3e91df190995932ab2ce9ed980e913990e320235f8eda153ee' 
  AND token = 'bI9k70PvGi/5y4lLV8LK9QoUV1ULZXarNILiiBuD3Bo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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