SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a02bca5c1b5cf732995abd500da997c195364ebbe90e3d13300ad13d8df5f276' 
  AND token = '4L8HPoN4CvOWZVs0IP7kPE+VwzaQ/5ezy8Ame7xEvCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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