SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aad418492d0ce10005354925f90e8dcdc21e2b575b207ee201a2046bf83e701' 
  AND token = 'pj1b2sLAd+xAsAIbdDLaxyksEijV+MmK5goIeU3G70w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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