SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f9141e353af3360fab3377afadddce07c515cc2542221f02186105fec7b0608' 
  AND token = 'mJPlggSFEJciW8kMGlNOzv0etyDhywLfDwbuQ5Zc160=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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