SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f55cd0509e2849c65e25c9f59a6ef8b9360e1b57250a3cdaed37528fb9b531bc' 
  AND token = 'QcsEchEO+QZJOu86Ea1uArWnHneCBKxvhSWdodBhK2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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