SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '78467f55b3bb79c3b983cc46382f2d819747c53288989b98842c07f9204e4193' 
  AND token = 'h7Ppw9rTqLmAFhq4tDIJ4sU1cbqDurSLx8N57oq2MXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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