SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba349e9990b39d86831c7f35056d894a107e5870caf5312d7f540528732c4ed9' 
  AND token = 'FDwJM+o0U5A/EVQd7GLGT8FSZfTCHupq2sOsUAn+fZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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