SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0e5b2e483b1bfb10158ce522d390c096187318d9b1b1d7d76c87899b37dca62' 
  AND token = 'o/PEngiNNxmjluhCT3qwjwVSlPAVMWbO63QAyhYzboE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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