SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4a0a5c6175bbc7034367e5e162bf87fa8c2244710b893e5578a2f97f65ea63e' 
  AND token = 'IiPegvpSU+/YY3iSlk/jEGKO2uchJRXcfrskOxIVnKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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