SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84d3fdd4371eb9a91daa1b6e4336e6538de2786c48c728555696afffdf39f7dc' 
  AND token = 'NE5PXe9+1tDLHasxzynxYy5xmtRenbmNup0/3fVNI1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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