SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4e382f3da811a675285ac5824a44b4641058962416b1cdd38424782586cb3abe' 
  AND token = 'QZxr4gw9nderWsE0xg9rjKkCVKO0KImyeVo2WuAzqDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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