SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53a9d0fd654bea3bc5bcd41ff389a28a7329ce9b7503ded3b8f17818f69511e2' 
  AND token = 'ynWEmAYNpZAniRBeHAWXPF1NFPmlqrMWd3aQHoVDfF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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