SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96e5e9c07e7401ff8c0cd33fa98a55706a016204063bb8d9e50ea81b1ce529c8' 
  AND token = 'ThvxO4KGFkZsnuaHBy35kRp1CzT/ewZuiuAINE33a0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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