SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2b2cf4d183dbef52c8686423f629135a747de528fa7a0fa210ddd8fa8f61cf23' 
  AND token = 'xPi1JEugLfiyzyWv7lxHNGXWHiUF8Bmm3MCPPInAeRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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