SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc3a0954aa2f59afc50d26381741a9ec8a03376f567dd747129d39def7d5fa08' 
  AND token = '3AYSochVwXFbT+anX+TflnjOg69BUjh4LnlkUTPqQX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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