SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4a03bc40c44de003804155893c74da8750182c6c811834a98a7da8ddbae37d2' 
  AND token = 'UQ5Hhf2GnAd6c+c2S2192B7wudoTMgfgGYMKQm1OLoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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