SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a86d54b9210cd912aec8153ac9beff3d356f5c16893817585c44cd4e1bbfff71' 
  AND token = 'l7gJzlm9XcHADXw91M4E+o6+spCNFhtjVTKjQSHh6rY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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