SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9362096da3da65f001c3187e8cc99a52afda3a7c82eaf6fb628af9cad4da5e1a' 
  AND token = 'fU/pDCvfw9lHF3iV/GSj4Gr62xXJAfI/gi31612tOMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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