SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5854d8f65249ceb4b404c356edfcccdf8337b1da352cd60a69006ac5d3872b72' 
  AND token = 'Ah8u9xm811Y0fVGKnXARLI3CObZfj7KdyEUSHwIVBNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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