SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31939a0e8724809f2a7048896a418d2598d5c53a133a65b10de48674657ebbe0' 
  AND token = 'NhNTEnmcqcuaPeO2on0kPpVKoK2WkffrWUsUwG08X04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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