SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e3010db008375c07f0f058455933ec9cd4f97d3985d26fdfa77265c7ea0bda4' 
  AND token = 'E2ER4GsRwbH3v0RRNCoeLw93w99o5/FbEMvGbXA4lA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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