SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '761443afb92ef638aa059965963b8fdd3b336b0c008116a58545c62d385c970d' 
  AND token = 'yv/E9L5xRq1trfYga79+5JG21BK1qkbjqZs98INsw7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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