SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd742e8141f90099e762d0f9d5fc70b17ca6a8f70d83a402d4c8ac71214a1adf1' 
  AND token = 'Qp74baT+3RVvfNAhDDdQ2RUUlAwvU62kgt8cYOE2z4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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