SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e67ebd8190368872d6e70aaf9c982ec997da3254f3b8ce9e51b2656afa152c74' 
  AND token = 'PntFfXEZu9eAkwvXgd5J3DmFtnXh4WHtoq4pGbLF/Q8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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