SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90256ca44eac98d079a2d8e5f19f6362d85f56928498a24f6121ffd12160570a' 
  AND token = 'umVX2YG3HfO2IO88TIeAd949BZ7iICRwDn72sP34z7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}