SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e02cd935188cc8e67ff3304c4b64e7f61efc8f20778c12c8e6cfa0b6b9d6a475' 
  AND token = '9+2mV2hQ5sBHio55k2uuj5O1oT3oYX8yLgJPJpXGvKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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