SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d2c445dd4fdc3c8c088b8b150160c0b367040a0749352dcdfedd10161bb2d18' 
  AND token = '0QCw+6RHNk31ZuWWStDLkpDec5dCRDkYdPIaiIvPmco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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