SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8508995df581db73da95b425b54bd8c4343abe33077c153b83f667f85145948f' 
  AND token = 'AZ3PgYFBLZv6p67v2h/z0TNO+7nn2/2G19NAxvPYYOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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