SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8f7bfccf62e17ec24aba9e2c3836e328838c6e69327e41814453cf3df2ae1ef' 
  AND token = 'OLF8DUxTSM3j4QP3tceiWg+aolg0USl2H/NTEfp0XPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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