SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52ce9295815db00ac61fc96806026aa8ca80cf1b887f9b6228718425304a0d09' 
  AND token = 'q7kzSLneNc7HCqkpfE/ik/xGC6YlsdKbNVEp43/LCTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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