SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df49667692f2cccb8b7158c37fa81485d77a456372b4a1069feabf825595511a' 
  AND token = 'vEmhF/sVICZMNTqLO60GXq4Gd6EI+aDcTmebXFNnGvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}