SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eac4535a58642d0b1ba9110b591bce54227757a2c4635361a83352fdab83fbdc' 
  AND token = 'byU26TJhidXOaV1M9B+VKQjyz5bykOm5mS5EPuaz+WE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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