SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '210213e0709e11a5bde7fc5d1a51ac5e15ad0e6187c52ef985fa19bbcec5b727' 
  AND token = 'dEOiPrEgjmuDZeUpTpRzhl5lPe/TpDJKl3mqPetp6R0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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